Name: 4Level
Author: Robert Poetzsch

FeaturesFunktionen

A clear picture of your fitness.Ein klares Bild deiner Fitness.

4Level turns your Strava activities into a clear picture of your fitness.

4Level macht aus deinen Strava-Aktivitäten ein klares Bild deiner Fitness.

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YOUR LEVEL, 1 TO 100

One number that combines three things:

Fitness — your training load over the last six weeks
Capacity — your running VO₂max or cycling watts per kilo
Consistency — how many of the last twelve weeks you trained

The level is calculated for every single day back to your first activity, using only what was known on that day. Scroll through years of history and see exactly when you peaked.

DEIN LEVEL VON 1 BIS 100

Eine Zahl aus drei Bausteinen:

Fitness – deine Trainingsbelastung der letzten sechs Wochen
Leistungsfähigkeit – deine VO₂max beim Laufen oder Watt pro Kilo beim Radfahren
Konstanz – wie viele der letzten zwölf Wochen du trainiert hast

Das Level wird für jeden einzelnen Tag bis zu deiner ersten Aktivität berechnet – nur mit dem, was an diesem Tag bekannt war. Blättere durch Jahre und sieh genau, wann du in Topform warst.

🔋

FORM, NOT JUST FITNESS

Fitness, fatigue and form (CTL, ATL, TSB) show whether you are fresh, building or overloaded — with a plain-language hint what that means for your next session.

FORM STATT NUR FITNESS

Fitness, Ermüdung und Form (CTL, ATL, TSB) zeigen, ob du erholt, im Aufbau oder überlastet bist – mit einem Hinweis in klaren Worten, was das für deine nächste Einheit heißt.

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RACE PREDICTIONS

Predicted times for 5 km, 10 km, half marathon and marathon, based on the pace and heart rate of your recent runs.

WETTKAMPFPROGNOSEN

Zielzeiten für 5 km, 10 km, Halbmarathon und Marathon aus Tempo und Herzfrequenz deiner letzten Läufe.

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RUNNING AND CYCLING

Yearly distance goal with a marker where you should be today
This year against last year and your best year
Weekly volume and records
All years at a glance

LAUFEN UND RADFAHREN

Jahresziel mit Markierung, wo du heute stehen solltest
Dieses Jahr gegen das Vorjahr und dein bestes Jahr
Wochenumfang und Rekorde
Alle Jahre auf einen Blick

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EVERY ACTIVITY

All sports in one searchable list, each with the training load it added.

JEDE AKTIVITÄT

Alle Sportarten in einer durchsuchbaren Liste, jeweils mit der Belastung, die sie gebracht hat.

Transparent: every value shows whether it was measured or estimated, and the whole formula is explained in the app. The level is a training aid, not a medical assessment.

Requires a Strava account. 4Level is not affiliated with Strava. Try the demo without any account.

Nachvollziehbar: Jeder Wert zeigt, ob er gemessen oder geschätzt ist, und die ganze Formel wird in der App erklärt. Das Level ist eine Trainingshilfe, keine medizinische Einschätzung.

Benötigt ein Strava-Konto. 4Level steht in keiner Verbindung zu Strava. Die Demo funktioniert ohne Konto.

LegalRechtliches

Privacy Policy / Datenschutzerklärung

Last updated / Stand: 2026-09-27

English

4Level is made by Robert Poetzsch (robspace.de). Contact: support@robspace.de.

What the app processes. When you connect your Strava account, the app loads your Strava profile (name, sex, weight, FTP, heart-rate zones) and your activity summaries (date, sport, distance, duration, elevation, heart rate, power) directly from Strava's API to your device. It calculates statistics and your fitness level on the device.

Where the data lives. Only on your iPhone/iPad. Activities are stored in the app's private storage and excluded from iCloud backups; the Strava access is stored in the iOS Keychain. There is no 4Level server, no user account, no analytics, no advertising, no tracking and no third-party SDKs. The developer receives none of your data.

Strava. The connection uses Strava's OAuth sign-in. Strava's own privacy policy applies to your Strava account (strava.com/legal/privacy). 4Level is not affiliated with Strava.

Your control. Settings → "Disconnect from Strava" revokes the app's access at Strava. "Disconnect and delete data" also removes all stored activities from the device. Deleting the app removes everything.

Health information. The fitness level is a training aid, not a medical assessment.

Deutsch

4Level ist von Robert Poetzsch (robspace.de). Kontakt: support@robspace.de.

Was die App verarbeitet. Wenn du dein Strava-Konto verbindest, lädt die App dein Strava-Profil (Name, Geschlecht, Gewicht, FTP, Herzfrequenzzonen) und die Zusammenfassungen deiner Aktivitäten (Datum, Sportart, Distanz, Dauer, Höhenmeter, Herzfrequenz, Leistung) direkt über Stravas Schnittstelle auf dein Gerät. Statistiken und dein Fitnesslevel werden auf dem Gerät berechnet.

Wo die Daten liegen. Nur auf deinem iPhone/iPad. Aktivitäten liegen im privaten Speicher der App und sind von iCloud-Backups ausgenommen; der Strava-Zugang liegt im iOS-Schlüsselbund. Es gibt keinen 4Level-Server, kein Benutzerkonto, keine Analyse, keine Werbung, kein Tracking und keine Drittanbieter-SDKs. Der Entwickler erhält keine deiner Daten.

Strava. Die Verbindung nutzt Stravas OAuth-Anmeldung. Für dein Strava-Konto gilt Stravas eigene Datenschutzerklärung (strava.com/legal/privacy). 4Level steht in keiner Verbindung zu Strava.

Deine Kontrolle. Einstellungen → „Von Strava trennen“ widerruft den Zugriff der App bei Strava. „Trennen und Daten löschen“ entfernt zusätzlich alle gespeicherten Aktivitäten vom Gerät. Das Löschen der App entfernt alles.

Gesundheitsangaben. Das Fitnesslevel ist eine Trainingshilfe, keine medizinische Einschätzung.

LegalRechtliches

Impressum (Legal Notice)

Information in accordance with Section 5 TMG (German Telemedia Act)

Robert Poetzsch
Brückenstr. 8A
65719 Hofheim am Taunus
Germany

Contact

Email: support@robspace.de
Website: robspace.de

EU DSA Trader Status

The operator of this app is acting as a non-trader within the meaning of the Digital Services Act (DSA, Regulation (EU) 2022/2065). The app is developed and published by a private individual and is not part of a commercial trade or business activity in the traditional sense. EU consumer protection law regarding the right of withdrawal therefore does not apply.

Responsible for Content pursuant to Section 55(2) RStV

Robert Poetzsch, Brückenstr. 8A, 65719 Hofheim am Taunus, Germany.

Liability for Content

As a service provider, we are responsible for our own content on these pages in accordance with general legislation pursuant to Section 7(1) TMG. According to Sections 8 to 10 TMG, however, we are not obligated to monitor transmitted or stored third-party information or to investigate circumstances that indicate illegal activity. Obligations to remove or block the use of information under general law remain unaffected. However, liability in this respect is only possible from the point in time at which we become aware of a specific legal infringement. If we become aware of any such legal infringements, we will remove the relevant content immediately.

Liability for Links

This website may contain links to external third-party websites over whose content we have no control. Therefore, we cannot accept any liability for this third-party content. The respective provider or operator of the linked pages is always responsible for the content of the linked pages. The linked pages were checked for possible legal violations at the time of linking. Illegal content was not recognizable at the time of linking. However, permanent monitoring of the linked pages is unreasonable without concrete evidence of a legal violation. If we become aware of any legal infringements, we will remove such links immediately.

Copyright

The content and works on these pages created by the site operator are subject to German copyright law. Duplication, processing, distribution, and any form of commercialization of such material beyond the scope of copyright law requires the prior written consent of its respective author or creator. Downloads and copies of this site are only permitted for private, non-commercial use. Insofar as the content on this site was not created by the operator, the copyrights of third parties are respected. In particular, third-party content is marked as such. Should you nevertheless become aware of a copyright infringement, please inform us accordingly. If we become aware of any infringements, we will remove such content immediately.

Third Parties

4Level is not affiliated with Strava. Apple Inc. is not responsible for the app, its content, or any claims related to the app.

4Level — Version 2.0
© 2026 Robert Poetzsch

4Level is developed as a personal project in my free time.
Responses to support inquiries may take some time.
Bug reports are always welcome and appreciated!

4Level

Your fitness level, 1 to 100Dein Fitnesslevel von 1–100